A leading charity is launching a campaign to persuade more mid-career professionals to volunteer overseas.

One teacher in her 20s tells BBC News website why she left Yorkshire to spend two years working in Pakistan and why she hopes others will follow her example.

After just two years as a teacher Aimee Low wondered whether she had enough experience to work overseas as a trainer.

But she found that because methods of teaching were very traditional she was able to pass on valuable new skills to local teachers in Pakistan.

Miss Low, 27, is now back home in Driffield, east Yorkshire, after spending two years training teachers from nine schools in the state of Peshawar.

"I kept asking my placement adviser if I really did have enough experience do a teacher training job.

"But as I learnt from other volunteers, I did. Education standards are very low so even as a less experienced teacher I could share with them really helpful methods and activities that were different to the traditional chalk-and-talk approach."

She says she can understand why young people might be deterred from volunteering for financial reasons but she urged them to give it a go.

A major advertising campaign

"I'd recommend it to any teacher. If everyone could spend some time living in a completely different culture, we'd all be more tolerant of one another.

"It broadens your horizons and makes you a better communicator. What I enjoyed so much is that it was so completely different to anything that I could have experienced in England."

Miss Low's mother Sheranne is also a teacher and the two women set up a pen-pal link between schools in Yorkshire and Peshawar, so children in both countries were able to learn more about life in another country.

The pressures of holding on to a good job and getting on the property ladder are preventing Generation X-ers from volunteering overseas

Judith Brodie, director of VSO UK

Perhaps surprisingly, fewer and fewer volunteers are Miss Low's age. They are more likely to come from her mother's generation.

Voluntary Service Overseas, the charity that recruited her, says the number of volunteers in their late 20s, 30s and 40s has dropped dramatically from almost 79% in 2000, to just 48% in 2006.

The lack of 'Generation X' mid-career volunteers has left VSO struggling to fill some placements, including 150 primary school jobs.

The charity is now launching a major advertising campaign aimed at people aged 25-45.

NUMBER OF OVERSEAS VOLUNTEERS EACH YEAR, BY AGE

18-24 year-olds - 230,000

25-35 year-olds - 99,000

55 plus - 200,000

Source: Mintel, July 2005

Judith Brodie, director of VSO UK, said: "VSO's experience is showing that the pressures of holding on to a good job and getting on the property ladder are preventing Generation X-ers from volunteering overseas.

"Attitudes towards taking a gap year seem to be changing, as the under-50s take time off to travel, but put off volunteering until retirement."

She urged employers to help by allowing people to return to their jobs after taking time out to volunteer overseas.

She added: "Volunteering overseas isn't just the preserve of students or golden-gappers."

Father-of-three David Palmer, 58, can understand why it is easier for older people to volunteer overseas.

David Palmer volunteered on a project in Ghana

He spent decades working his way up from clerk to managing director of his own insurance company and bringing up his children.

"It's not easy to drop everything but I had come to a point in my life where I was able to do it financially and in terms of responsibility - my children were in their 20s."

He needed a sound constitution to deal with stomach upsets, power cuts, no hot water and intermittent cold water and flexibility and initiative to help people with disabilities in Ghana to set up a minibus service, chalk-making business, library and coffee shop.

Mr Palmer, who lives in Sale, Cheshire, said: "We're a generation of fortunate people, baby boomers who have a few bob behind us because we lived through property booms.

"We're also fitter and better trained, yet we still have a bit of adventure left in us."

But Mr Palmer's "Generation X" children help to dispel any suggestions that younger people are deterred from volunteering through selfishness.

His daughters, aged 25 and 30, helped to raise money for the project he worked on and his son Rob, 27, who is training to be a chiropractor, spent three months volunteering alongside his father in Ghana.